Prediction of hybrid performance for Fusarium head blight resistance in triticale (xTriticosecale Wittmack)

Like other small grain cereals, triticale (xTriticosecale Wittmack) is also affected by Fusarium head blight (FHB) which is a serious plant disease leading to yield losses and to a contamination of feed and food by harmful mycotoxins. Use of resistant varieties is the most effective way to manage FHB infections. More recently, commercial hybrid breeding in autogamous cereals has received increased interest. Therefore, we built a bridge between hybrid and resistance breeding and conducted a multi-environmental field trial using deliberate inoculation with Fusarium culmorum to: (i) evaluate different hybrid prediction approaches based on phenotypic and/or genomic data; (ii) compare the effect of cytoplasmic male sterility (CMS) inducing cytoplasm and normal (N) cytoplasm on FHB resistance. We evaluated 226 single cross hybrids, their paternal and maternal lines in both CMS- and N-cytoplasm. Our analysis revealed a large genetic variation for FHB resistance. Single cross hybrids tended to be more resistant than their parental lines. We observed a close association between N-lines and CMS-lines for FHB resistance. We found a predominance of sigma (GCA) (2) over sigma (SCA) (2) for FHB resistance. Correlation between the sum of general combining ability (GCA) effects and hybrid performance was high for FHB resistance. Mid-parent performance served as a moderate indicator for FHB resistance of single crosses. Best linear unbiased prediction of hybrid performance based on relatedness between tested and untested genotypes estimated by marker data showed great potential for hybrid prediction when no reliable per se information or GCA estimates are available.